1. Field of the Invention
The present invention relates to a metal oxide semiconductor (MOS) transistor and fabricating method therefor. More particularly, the present invention relates to a metal oxide semiconductor (MOS) transistor and fabricating method therefor capable of preventing the metal silicide layer inside the MOS transistor from any damages.
2. Description of the Related Art
In the fabricating process of metal oxide semiconductor (MOS) transistors, spacers are often removed after forming a metal silicide layer to increase channel mobility. Thereafter, according to whether the MOS transistor is an n-type or a p-type device, a high-tensile or high-compression dielectric layer is formed on the substrate to serve as a contact etching stop layer (CESL).
However, most spacers are fabricated using silicon nitride material so that spacers are generally removed using hot phosphoric acid. Thus, in the process of removing the spacers, the metal silicide layer may be damaged by a significant quantity of hot phosphoric acid. In particular, the damage inflicted upon the metal silicide layer when the metal silicide layer is made of nickel silicide is more severe. Ultimately, the performance of the transistor device is adversely affected.